Lawmakers are set for a clash in the Senate Monday over unemployment benefits, with Democrats calling for a no-strings-attached extension of long-term benefits and Republicans insisting that any new spending be offset by cuts elsewhere.

Senate Majority Leader Harry Reid said Sunday he is hopeful Republicans will sign on to a proposal, set for a test vote Monday afternoon, from Sens. Jack Reed, Rhode Island Democrat, and Dean Heller, Nevada Republican, that would fund benefits for three months and find offsets later.

“There’s 55 of us, and there’s 45 of them,” the Nevada Democrat said on CBS’s “Face the Nation.” “It would seem to me that five Republicans in the Senate should agree with the Republicans around the country. Republicans around America want us to do something to extend these benefits.”

Mr. Heller, Mr. Reid said, is not “some maverick that is out spewing socialism.”

The looming stalemate is just the latest in a series of budget fights stretching back three years, to when the GOP captured control of the House and began to put the breaks on federal spending.

Sen. Charles E. Schumer, New York Democrat, told reporters Sunday that he wasn’t sure if Democrats had the votes yet to clear the 60-vote threshold.

“The vote is close, and if we don’t get the 60, we’ll come back at this issue,” he said.

At least one Republican, Rep. Lamar Alexander of Tennessee, has already said he will vote no on the issue.

“I will not vote to bring this legislation to the floor unless senators have an opportunity to debate and vote on the many good ideas for helping unemployed Americans find a job,” he said Sunday in a statement.

The Reed-Heller proposal includes no offsets for the cost of the extension — some $6.5 billion — making it unlikely the bill could clear Congress.

House Ways and Means Committee Chairman Dave Camp, Michigan Republican, does not support an extension of the federal benefits because workers who lose their jobs already have access to about six months of state-paid unemployment. The federal program was always meant to be a temporary fix, but has now been in place for six years.

“Despite a dozen extensions, academic research suggests the program has actually hurt, rather than helped, the job creation that the unemployed need most,” Michelle Dimarob, Mr. Camp’s spokeswoman, said Friday. “It is time to focus on policies that will actually lead to real economic opportunities for families who are trying to get back on their feet and back into the workplace.”

House Speaker John A. Boehner said last month that he would consider an extension only if it was fully paid for and included other provisions to jump start the economy — neither of which are in the Senate plan.

Federal benefits for the long-term jobless, which passed Congress when the economy began to slump in 2008, expired on Dec. 28.

Democrats hope that highlighting stories of those who’ve lost their benefits will pressure Republicans to accept a bill even if it adds to the deficit.

“I think the more the words of the long-term unemployed come forward, I think it will leave Congress with no alternative but to extend unemployment insurance,” said Rep. Sander M. Levin, ranking Democrat on the House Ways and Means Committee.